Polymer Science Quiz

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The polymer in solution is called the ______.

flash

If no flash occurs, it is possible that there was insufficient ______ in the mold.

dough

In Stage 4, the mass becomes more cohesive and ______-like.

rubber

The flask must be closed properly with a -to- contact.

metal Signup and view all the answers

In Stage 5, the dough has completely ______ and cannot be packed into the mold space.

hardened Signup and view all the answers

The bench curing process involves keeping the flask at a room temperature for - minutes.

30-60 Signup and view all the answers

According to ADA SPEC.#12, the dough should be moldable for at least ______ minutes.

5 Signup and view all the answers

The heating process of the resin is essential to achieve the ______ of the resin.

polymerization Signup and view all the answers

Synthetic resin is composed of ______, which are complex molecules of high molecular weight.

polymers Signup and view all the answers

The term ______ refers to the molecular fragment with an unpaired electron.

free radical Signup and view all the answers

In the polymerization process, low molecular weight compounds called ______ are converted to high molecular weight compounds.

monomers Signup and view all the answers

Thermoplastic materials can be molded without chemical change by softening them under ______.

heat Signup and view all the answers

A ______ is formed from large numbers of single molecules during polymerization.

macromolecule Signup and view all the answers

Copolymers consist of two or more different ______.

monomers Signup and view all the answers

Thermoset materials undergo a ______ during the molding process, making them chemically distinct from their original substance.

chemical reaction Signup and view all the answers

______ are materials that may include adhesives and root canal sealers.

Restorative materials Signup and view all the answers

Fracture of the denture can occur from ______ while polishing.

breakage Signup and view all the answers

Athletic mouth protectors and orthodontic appliances are made from ______ materials.

synthetic resin Signup and view all the answers

Internal ______ are found within the denture base, often in the thick portions.

porosities Signup and view all the answers

A ______ polymer has a high molecular network structure that is more durable.

cross-linked Signup and view all the answers

One cause of porosities is the vaporization of the ______.

monomer Signup and view all the answers

Soft liners are used for severe undercuts of the ______.

ridge Signup and view all the answers

Acrylic resin teeth are made from acrylic and modified acrylic ______.

polymers Signup and view all the answers

Heat-cured Resin is processed by ______ to form a single large molecule of high molecular weight.

heating Signup and view all the answers

Self-cured Resin is also known as ______ and is chemically activated to cure at room temperature.

auto-polymerizing resin Signup and view all the answers

Light-cured Resin polymerizes through exposure to ______ light.

halogen Signup and view all the answers

Condensation Polymerization is also known as ______-growth polymerization.

step Signup and view all the answers

In Condensation Polymerization, new atoms join with others to form ______, such as water or ammonia.

by-products Signup and view all the answers

Addition Polymerization is characterized by an ______ reaction.

addition Signup and view all the answers

Poly (methyl methacrylate) is a type of ______ commonly used in dentistry for its clarity and stability.

polymer Signup and view all the answers

Acrylic Resins are derivatives of ______.

ethylene Signup and view all the answers

The principal component of the powder in dental resins is Poly (Methyl Methacrylate), which is present as small ______ or pearls.

spheres Signup and view all the answers

For Addition Polymerization, a requisite is the presence of a ______ bond and a free radical.

double Signup and view all the answers

Organic Amine acts as an organic accelerator to decompose ______ at room temperature.

peroxide Signup and view all the answers

Methyl methacrylate is a clear ______ liquid at room temperature.

transparent Signup and view all the answers

The boiling point of methyl methacrylate is at ______ °C.

100.8 Signup and view all the answers

The first step in denture base construction is ______ making.

Impression Signup and view all the answers

Construction of the master/working cast follows the ______ making step.

Impression Signup and view all the answers

After wax elimination, the assembly is placed into boiling ______ for 5-10 minutes.

water Signup and view all the answers

One of the functions of applying colorgard is to prevent ______ from entering the resin.

water Signup and view all the answers

The metal flask used in investing has ______ parts.

four Signup and view all the answers

The packing of resin into the mold space utilizes ______ and injection molding techniques.

compression Signup and view all the answers

The curing stage follows the ______ closure in the denture base construction process.

trial Signup and view all the answers

What is the primary goal of the dough forming time according to ADA SPEC.#12?

It must be attained in at least 20 minutes from the start of mixing. Signup and view all the answers

Describe the significance of stage 4 in the polymerization process.

Stage 4 is where the mass becomes cohesive and rubber-like as monomer evaporates. Signup and view all the answers

What happens to the dough during the stiff stage?

The dough has completely hardened and can no longer be packed into the mold space. Signup and view all the answers

Explain the role of the metal-to-metal contact during the flask closing process.

It ensures a proper seal for effective curing and processing of the resin. Signup and view all the answers

What is the purpose of bench curing in the molding process?

It allows equalization of pressure and stabilization of the mold at room temperature. Signup and view all the answers

How does the curing cycle affect the properties of the resin?

The curing cycle, which involves heating, initiates polymerization and enhances resin durability. Signup and view all the answers

What is the significance of preventing flash during the molding process?

Preventing flash ensures a smooth and non-tacky finish of the final product. Signup and view all the answers

Why is it important for the dough to remain moldable for at least 5 minutes during processing?

This allows sufficient working time to shape and pack the resin properly into the mold. Signup and view all the answers

What is the main characteristic of self-cured resin regarding its curing process?

It is chemically activated and cures at room temperature. Signup and view all the answers

How does light-cured resin initiate the polymerization process?

It polymerizes through exposure to halogen light. Signup and view all the answers

What type of by-products are typically produced during condensation polymerization?

By-products such as water or ammonia are produced. Signup and view all the answers

Identify one primary use of elastomeric impression materials.

They are used for taking accurate dental impressions. Signup and view all the answers

What is the significance of a double bond in addition polymerization?

It acts as a requisite for the polymerization process to occur. Signup and view all the answers

What process is referred to as 'step-growth polymerization'?

Condensation polymerization is referred to as step-growth polymerization. Signup and view all the answers

Describe the primary characteristic of addition polymerization compared to condensation polymerization.

Addition polymerization does not produce any by-products. Signup and view all the answers

What is Poly (Methyl Methacrylate) commonly used for in dentistry?

It is used as a principal component in various dental resins. Signup and view all the answers

What are acrylic resins derived from?

Acrylic resins are derivatives of ethylene. Signup and view all the answers

What types of materials can be made using light-cured resins?

They can produce crowns, veneers, and other aesthetic dental applications. Signup and view all the answers

What is polymerization, and what are its end products?

Polymerization is the conversion of low molecular weight compounds called monomers into high molecular weight compounds known as polymers. Signup and view all the answers

Define thermoplastic and thermoset materials based on their thermal behavior.

Thermoplastic materials can be molded without chemical change by softening under heat, while thermoset materials undergo a chemical reaction during molding, making them infusible and insoluble. Signup and view all the answers

What role do free radicals play in the polymerization process?

Free radicals are crucial in initiating the polymerization process by providing an unpaired electron needed for the reaction to occur. Signup and view all the answers

Explain what a cross-linked polymer is.

A cross-linked polymer is a high molecular weight polymer where the chains are connected by covalent bonds, enhancing its durability and resistance. Signup and view all the answers

What distinguishes copolymers from other polymers?

Copolymers are made from two or more different types of monomers, resulting in unique properties compared to homopolymers, which consist of only one type of monomer. Signup and view all the answers

How are athletic mouth protectors typically fabricated?

Athletic mouth protectors are commonly made from thermoplastic materials that can be molded and shaped for a comfortable fit. Signup and view all the answers

Describe the impact of thermal behavior on resin applications in dentistry.

The thermal behavior of resins is critical as thermoplastics can be remolded and reused, while thermosets provide more stable and durable applications. Signup and view all the answers

What is the significance of softening agents in synthetic resins?

Softening agents, or plasticizers, are added to synthetic resins to improve their workability and flexibility for various dental applications. Signup and view all the answers

Why are self-cured resins also referred to as chemically activated resins?

Self-cured resins are referred to as chemically activated because they undergo polymerization at room temperature through a chemical reaction, without the need for external heat sources. Signup and view all the answers

What characteristics make poly(methyl methacrylate) a preferred resin in dentistry?

Poly(methyl methacrylate) is favored in dentistry due to its clarity, stability, and ease of processing, making it ideal for dental prosthetics and appliances. Signup and view all the answers

What are the common causes of fracture in denture bases?

Fractures can occur due to dropping the denture, excessive pressure during separation, excessive grinding, or inadequate curing time. Signup and view all the answers

Describe the process and purpose of trimming and polishing denture bases.

Trimming involves removing excess resin to prevent injury to soft tissues, while polishing should avoid heat production to prevent warpage. Signup and view all the answers

What are internal porosities and list two causes of their development in denture bases.

Internal porosities are flaws found within the denture base, often caused by the vaporization of the monomer and too rapid curing. Signup and view all the answers

Explain the purpose of soft liners in denture fabrication.

Soft liners are used to provide cushioning for sore residual ridges and are beneficial for patients with dental ridges that have severe undercuts. Signup and view all the answers

What is the role of self-curing acrylic resin in denture repair?

Self-curing acrylic resin is used for repairs due to its ability to bond well and cure at room temperature, making it convenient for denture repairs. Signup and view all the answers

What role does Benzoyl Peroxide play in the polymerization process of acrylic resins?

Benzoyl Peroxide acts as an initiator in the polymerization of acrylic resins. Signup and view all the answers

How does Titanium Dioxide affect the translucency of dental polymers?

Titanium Dioxide controls translucency by increasing the opacity of the material. Signup and view all the answers

What is the significance of the Sandy Stage in the polymerization of acrylic resins?

The Sandy Stage indicates the initial damp consistency of the resin before achieving a more workable state. Signup and view all the answers

What is the function of Dibutyl Phthalate in acrylic resin formulations?

Dibutyl Phthalate serves as a plasticizer in acrylic resin formulations. Signup and view all the answers

What components are typically used as inorganic pigments in denture base resins?

Inorganic pigments like mercuric sulfide, cadmium sulfide, and ferric oxide are commonly used. Signup and view all the answers

Explain the purpose of Hydroquinone in the storage of acrylic resins.

Hydroquinone acts as an organic inhibitor that prolongs the storage life of acrylic resins. Signup and view all the answers

What is the goal of using cross-linking agents like Glycol Dimethacrylate in acrylic resins?

Cross-linking agents like Glycol Dimethacrylate enhance resistance to surface cracks and crazing. Signup and view all the answers

What changes occur in the polymer structure during the Rubbery Stage of polymerization?

During the Rubbery Stage, the mass becomes more elastic and retains some shape upon deformation. Signup and view all the answers

Why are multifaceted methacrylates like UDMA employed in acrylic resins?

Multifunctional methacrylates like UDMA improve the mechanical properties and flexibility of the resins. Signup and view all the answers

Describe the general impact of Talc or Gelatin when added to acrylic resin formulations.

Talc or Gelatin is added to prevent the cohesion of beads or pearls during storage. Signup and view all the answers